Red Bull and its Effect on Endurance of Female Athletes

SummaryThis research tested the effects of Red Bull, an energy drink, on the performance of women athletes. Participating in this study were 15 female soccer players, about 20 years of age. They were asked to drink either 255 ml (equal to one serving) of Red Bull or a placebo drink, an hour before their daily exercise. During this period, their heart rates, ratings of perceived exertion (RPE) and sprint times were recorded. There was no significant effect on any of these variables, indicating that a single serving of Red Bull gave no benefits in sprint-based exercise in women athletes.

Introduction
Caffeine is known to reduce fatigue and increase attention and alertness. It is also considered to be a performance-enhancing aid. However, its beneficial effects on activities requiring high strength are unclear. Most athletes consume caffeinated energy drinks like Red Bull, containing 80 mg of caffeine per serving. Recent studies have shown that Red Bull has a positive effect on stamina in aerobic, as well as anaerobic, exercises like bench pressing or cycling. Although the effects of high doses of pure caffeine have been tested, lower doses (as in Red Bull) need more investigation. In this study, the researchers hypothesized that Red Bull consumption will improve the sprint performance in women athletes.

Methods
* This study involved 15 women soccer-players of comparable age, weight and height. All the participants had been soccer players for 12 to 15 years and were currently involved in an intense exercise routine of 12 hours per week.
* One serving of Red Bull or a placebo drink was given to them an hour before exercising. The participants were asked to report if they felt any side effects after consuming the drinks.
* They were then asked to complete 24 sprints by doing three sets of eight sprints each. Their sprint time, heart rates and levels of fatigue were recorded during the exercise.
* The same procedure was repeated by reversing the drinks; the placebo drink was given to those who had consumed Red Bull in the first part of the study, and vice versa.

Results
* Across the three sets, the sprint time differed for each athlete. However, no difference was observed between consumers of the placebo drinks or Red Bull. A better performance did not seem to be related to the consumption of either of the two drinks.
* Five participants performed better with Red Bull and five others with placebo drinks. The remaining five participants showed no difference in performance with or without Red Bull.
* The heart rates increased significantly, indicating the high-intensity nature of their exercise. The heart rates of the fastest women in the Red Bull group were higher than the heart rates of the fastest women in the placebo group.
* Two of the participants reported side effects like stomachache and mild tremors after Red Bull consumption.

Shortcomings/Next steps
Since this study involved trained women athletes, the results cannot be applied to non-athletes, less active individuals, straight-line sprinters or men. Another limitation of this study is that it only tested a very low dose of caffeine available from one serving of Red Bull. In addition, the number of sprints performed in this study is not sufficient for testing the performance enhancing effects of Red Bull. The authors suggest future studies on the effects of higher doses of Red Bull on the performance of athletes in diverse sports involving high intensity exercises.

Conclusions
The intake of one serving of Red Bull an hour before exercise was found to have no effect on the performance of trained women sprinters. No significant difference in fatigue, tiredness and heart rate was noticed between the Red Bull and the placebo drinkers. These results are contradictory to those obtained from other studies. This may have resulted due to differences in the designs of these studies. While caffeine in small amounts may not have performance-enhancing effects on women athletes, higher doses of caffeine may increase stamina and reduce fatigue. In addition, small amounts of caffeine in energy drinks may be effective in lower-intensity workouts.